Syringe with progressively-graduated automatic action



Anc ACTION.

Patented May M, w29.

2 SHEETS-SHEET l.

COURNAND. SIVELY GRADUATED AUTOM APPLICATION FILED NOV.2B, i913.

SYHINE WITH PROGRES 1,416,614.,

'1. COUHNAND. SYRINGE WITH PROIASR'ESSIVELY GRADUATED 'A APPLICATION FILED NOV. 28,' I9I 1,41 6,6].4w l

UTCIMVATICl ACTION. 3.

Swoawboz Patented May I6, 1922.

2 SHEETS-SHEET 2.

MN it' 5 FAT ES est JULES COURNAND, OF PARIS, FRANCE.

SYRINGE lil/'1TH PROGRESSIVELY-GRADUATED AUTOMATIC ACTION.

raisers.

Application filed November 28, 1913. Serial No. 803,556.

(GRANTED UNDER THE PROVISIONS 0F THE ACT 0F MARGH 3, 1921, 41 STAT. L., 1313.)

To 1l/ZZ whom t may concern Be it lrnown that JULns GOURNAND, citizen of the French Republic, residing :at 28 Avenue de lpera, Paris, France, has invented certain new and useful Improvements in Syringes with progressively-Graduated Automatic Action, of which the following is a specification. j

This invention relates to a syringe that has a piston which is operated by a mechanical device and by means of which a progressive quantity of an anesthetic liquid for example can be injected at the desired place and at the required moment. This improved syringe can be used in any case of hypodermic injection and particularly in `dental operations.

For dental operations as carried out at the present time a hypodermic injection is effected in two stages, the first comprising the introduction and placing of the needle, the second the injection of the whole or a ortion of the contents of the syringe.

For the first phase the barrel of the syringe is conveniently held like a pencil, between the thumb, the fore-finger and thefmiddle finger.

For the second phase the body of the syringe is held like a cigar, between the middle finger and the fore-finger which are placed on the two grips arranged at the end of the barrel of the syringe, in order to enable a thumb placed on the piston rod and acting thereon to apply pressure.

rlhe changes of position effected by the lingers in order to pass from the first to the second stage are frequently attended with difliculty, because the patient may move and the incommoded operator cannot perform that operation as precisely and delicately as required, particularly in the case of diploicand regional punctures, and when the needle is mounted on a bent rod, a rod that is rendered necessary for reaching a. part of the buccol cavity that is not easily accessible. or is inacessible with a straight needle. Consequently theneedle may come out of the tissues or break in them.

in the second phase the syringe is not well placed for effecting a long pressure and at the same time for following the instinctive resistant movements of the patient.

The resistance presented by the tissues to the penetration of the injected liquid, sometimes necessitates a powerful action of the thumb, nay even of the palm of the hand,

and it is not infrequently observed that there is a sudden relaxation of the resistance, indicating a laceration of the tissues by the powerful pressure of the liquid, giving rise to traumatic accidents which are painful and serious. traumatic accidents there is reason for fearing accidents of a toxical kind in consequence of the diffusion over a large surface owing to the sudden irruption into the circulating stream of a large quantity of anesthetic whereas it ought to' be injected into a very circumscribed space, and very gently that is to say progressively so as to proportion the quantity of the anesthetic to the susceptibility of the patient. Finally a sudden inrush of liquid under powerful pressure causes intolerable pain owing to the fact that the tissues are already excessively distended through the inflammation.

Injections into the diplo and punctures for regional anesthesia necessitate that the syringe be accurately positioned.

These practical necessities show the advantage lst. Of holding the syringe in the position for the first stage so as to be always ready to follow the patient in his instinctive resistant movements, because in that position the syringe is well in hand.

2nd. Of injecting the liquid very slowly and progressively proportionally to the' susceptibility of the patient in order to prevent the liquid from being suddenly diffused in the tissues.

The syringe with automatic progressive action that contitutes the present invention 4ensures these advantages. j

Fig. l is a longitudinal sectional view of the device;

Fig. 2 isa longitudinal sectional view of a portion of the device taken on the plane indicated by the line 22 of Fig. l;

Figs. 3 and l are transverse sectional views taken on the planes indicated respec`' tively by the lines 3 3 and 4-4 `of Fig. 1

Fig. 5 is an end view of the device with the flexible member disconnected from the sleeve and the latter revolved through 900 from the position it is shown in in Figs. l to 4L;

Fig. 6 is a side elevation of the end of the flexible member; j

Fig. 7 is a perspective view of one end ofthe shaft upon which the worm is mounted; and

But independently of these straight or bent runs.

Fig. 8 is a similar view of one end of the hub which fits upon the shaft shown in Fig. 7.l rEhe cylindrical body or barrel 1 of the syringe which is of the usual form is provided with an external nipple 2, through which the needle 3 which may be' either rlhis needle is secured tightly and firmly by means of the cap 1- screwed on to this nipple. ln this body 1 the pistonis moved automatically and very slowly and forces into the needle 3 the anesthetic or other liquid contained in the body 1, and which is to be injected into the tissues.

Onto the body 1 opposite the nipple 2 a small box 5 is screwed which contains the mechanism for operating the piston-rod 6 of the syringe. The box 5 extends transversely of the body or barrel 1.

This mechanism consists of a worm 7 fixed ,on a shaft S that projects from the box 5 and a helicoidal or worm wheel 9 with a hub 10 that is screw-threaded to suit the pitch of the screw-thread of the piston-rod 6. The wheel 9 with its hub 10 constitutes a nut. The external cylindrical side of this hub is held in the box 5 concentrically to the axis of the rod 6 by means of two discs 11 and 12 attached one to the bottom of the box 5, thev other to the interior surface of its cover 13. 0n to this cover a sleeve 15 is fixed by means of screws 1/1. The sleeve has an end closure 16 in which an opening is drilledvwhich is partially circular at 17 and partially rectilineal at 18 opposite flat parts 19 of the piston-rod 6 which runs freely through it. This opening acts as a guide for the rod, and prevents it from turning. Beyond the closure 16 the piston-rodis furnished with a milled nut 2O fastened on to it.

The piston-rod is screw-threaded over the greater part of its length and it is screwed into the screw hub 10 of the helicoidal wheel 9, -a part of the screw'thrcaded portion being removed through two parallel flat surfaces formed on this rod. The flat surfaces 19 which surmount the screw-threaded part 6 are graduated for the purpose of ascertaining the extent to which the rod is pushed into the cylindrical body l. To the cylindrical end 21 of theV rod a piston 22, for example metallic, is attached, which has one or two peripheral grooves 23 as may be required. The cylindrical nipple 21. is lodged freely in the corresponding hollow of the piston 22 and a pin 24: connects this nipple with the piston rllhis non-ri gid arrangement of the piston on its rod is intended-to enable the piston. to move to a slight extent in the cylindrical body 1 so as to prevent the wedging of the piston against the inside of the body 1 which might happen in consequence of the slight play existing between the gearings 7 and 9. v

One of the novel features of this syringe provided with a mechanically operated piston consists in the arrangement whereby the shaft 3 of the worm 7 disposed at right angles to the longitudinal axis of the syringe 1 and situated at a distance from that axis equal to the sum of the radii of the pitch diameters of the worm 7 and wheel 9. The flexible device A has a swiveled connection with the box 5 so that its rotary shaft which. is disposed at right angles to the shaft may be kept in parallel relation to the longitudinal axis of the syringe.

This arrangement is very important for during use the syringe is held lbetween the middle nger and the fore-finger and the fore-linger placed at the height of the box 5 on its projecting' surfaces, so that the flexible device A containing the rotary shaft of the electric motor for example, connected firmly with the shaft 8 that contro-ls the syringe mechanism, partially `supports this syringe and thus relieves the operators hand, which is in no way incommoded by the fiexible shaft, whilst it moves the syringe in any direction. Furthermore ythe hand does not impede the rotary shaft of the flexible device.

The firm though easily removable connection between the end 4of the rotary shaft of the flexible device A and the operating shaft 8 is effected in the following manner: One end of the shaft 8 projects from one side of the box 5 and is provided adjacent this side of the box 5 with a disk 27. The projecting end of the shaft 8 extends through `a sleeve 25 and a terminal piece or collar 26 fixed thereto. rllhe terminal piece or collar 2G is enlarged at one end to provide it with an internal shoulder. The disk 27 is disposed .within the enlarged portion of the terminal piece or collar 26, and is confined between the `internal shoulder of the latter and a screw 98 extending through and projecting inwardly from the wall of the same. rfhus. the sleeve 25 and terminal piece or collar Q6 carried thereby may turn around the shaft 3 as an axis. the screw extei'xding beyond the edge of the disk 27 and serving to prevent the parts from "separating.I The end of the flexible device f1 is placed opposite a notch Q9 in the sleeve so that the pinion a on the end of the shaft 7) of the flexible device r-i will engage-a pinion c carried by a hollow hub (l which is revolubly mounted in the sleeve The shaftl is extended through `this hub (Z and is provided with a flat portion 8f) which engages a flat portion e in the bore of thehub (Z to effect a driving` connection between the latter and the shaft 8.' The shaft 8 is also provided. with a `circular groove 33, and this groove is to be engaged by the hook 32 of a plate 30 which is pivoted at 31 to the head of the flexible device A. When intesi/i this is done a square piece 311 pivoted at 35 on the sleeve is turned down on the head of the flexible device so that its projection 36 bears against the plate 3() and prevents it from becoming disengaged from the shaft 8. This construction apparently prevents,

the flexible device from becoming uncoupled from the sleeve 25.

The flexible device A constructed at its connect-ing end in the manner shown in the accompanying drawings, being capable of moving in all directions without its' connection with the shaft 8 ceasing, it is easy to understand that the operator holding the syringe between the middle finger and the forefinger, can move it in any direction without the rotat-ion of the shaft being` impeded. rThis rotation will only cease at the moment when the rotation of the shaft of the flexible device is arrested at the wish of the operator.

The syringe filled with liquid to be injected being connected, as just stated,v to the end of the shaft of the flexible device the latter being not yet set in rotation, the said syringe held between the third finger and the forefinger which are placed on the projecting surfaces of the box 5, the opera-tor puts the point of the needle 3 in the precise spot in the tissues where the anesthetic or other liquid is to be injected, without moving the hand but if necessary supporting the last two fingers of the hand against the patients teeth in order that the operators hand may easily follow the instinctive resistant movements of the patient without the operator having to fear that the needle may move and come out of the tissues, sets the shaft of the flexible device in rotation which causes rotation of the worm T, wheel 9 and of the hub 10 and movement of the piston to force the liquid slowly and progressively into the needle and the tissues. By stopping the rotation of the shaft of the flexible device at the required moment the injection is stopped.

Instead of being; entirely of metal the piston 22 may be lined with -asbestos for example or be made of india-rubber.

Vlhat he claims and desired to secure by Letters Patent is:

l. lnahypodermic syringe, the combination of a barrel, a screw threaded rod slidably but non-rotatably mounted in said barrel and carrying a piston at one end operable in said barrel, a nut rotatably mounted at one end of said barrel and meshing with said rod for moving` the latter and said piston longitudinally in said barrel, a flexible me1nber having a swiveled connection with said barrel, a flexible power driven rotary shaft mounted within said member, and gearing interposed between said shaft and said nut for rotating the latter, said gearing permitting` said member to swing upon its swiveled connection with said barrel to permit said member to be maintained in parallel relation with said barrel.

2, ln a hypodermic syringe, the combination of a barrel41 a gear casing fixed upon one end of said barrel and extending transversely of the same, a screw threaded rod slidably but non-rotatably mounted in said barrel and carrying a piston at one end operable in said barrel, a nut rotatably mounted in said casing and meshing with said rod for moving the latter and said piston longitudinally in said barrel, a flexible member leading to said casing and having a swiveled connection therewith. a flexible power driven rotary shaft mounted within said member, gearing mounted in said casing and between said shaft and said nut for rotating` the latter, said gearing permitting said member to swing` upon its swivelcd connection with said casing to permit said member to be maintained in parallel relation with said barrel.

3. In a hypodermic syringe. the combina4 tion of a barrel, a gear casing fixed upon one end of said barrel and extending transversely of the same, a screw threaded rod slidably but non-rotatably mounted in said barrel and carrying a piston at one end operable in said barrel, a nut rotatably mounted in said casing and meshing with said rod for moving the lat-ter and said piston longitudinally in said barrel, a sleeve extending from one side of said casing at right angles to said rod and having a swivelled connection to said casing, a flexible member leading` to said sleeve and havinga detachable connection with the same, said member being arranged at right angles to said sleeve, a flexible power driven rotary shaft mounted within said member, and gearing disposed in said casing and said sleeve between said shaft and said nut forrotating the latter, said gearing permitting said sleeve to turn upon its swiveled connection with said casing to permit said member to be maintained in parallel relation to said barrel.

a. ln a hypodermic syringe.l the combination of a barrel, a gear casing fixed upon one end of said barrel and extending transversely of the same, a screw threaded rod slidablv but non-iotatably mounted in said barrel and carrying a piston at one end operable in said barrel, a nut rotatably mounted in said casing and meshing with said rod for moving the latter and said piston longitudinally in said barrel, a sleeve eX- tending from one side of said casing right angles to said rod and having a swiveled connection to said casing, a flexible member leading to said sleeve and arranged at right angles thereto, a flexible power driven rotary shaft enclosed in said member, gearing mounted in said casing and said sleeve between said shaft and said nut for rotating the latter, part of said gea-ring being,I mounted upon a shaft extending through seid easing and longitudinally through Said Sleeve, one end of the last mentioned shalt having an annular groove therein, a, hook pivoted to said flexible member and engageztble with said groove for removably `fastening Said member to said last mentioned shaft and to seid sleeve and ineens for maintaining said hook in engagement with seid groove. l0 ln testimony whereof he has allixecl his Signature, in presence of two Witnesses.

JULES COURNAND. Witnesses MARCEL MAULVAULT, HANSON C. CoXn. 

